The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
An adjustable chuck of the type in widespread use for gripping workpieces of different sizes typically includes a plurality of jaws that is radially movable to grip and release a workpiece. The jaws are typically configured for retaining a specific workpiece; and when it is desired to use the chuck to grip different workpieces, different jaws are used. Accordingly, when it is desired to machine a different workpiece, the jaws on the chuck must be changed, which is a time consuming process.
Typically, the jaws of a chuck are attached to actuators that are located within a bearing that allows the actuators to pivot and move the jaws radially inwardly and outwardly to engage with and release the workpiece. The bearings are fractured into two pieces for assembly purposes. The use of fractured bearings, however, has drawbacks. For example, the two bearing halves must always be kept together in sets throughout the life of the bearing. Additionally, the fracture creates a gap in the bearing interface that allows grease to escape from inside the bearing during movement of the actuator. This, in turn, affects the efficiency and longevity of the bearing, actuator and, accordingly, the chuck. Moreover, the fracture can enable the bearing pieces to move slightly relative to one another as the chuck is actuated. The relative movement can affect the accuracy of the load imparted by the jaws onto the workpiece.